Similarly, I've noticed that friends who have sons are taken aback at how behavioural and physical problems are more prevalent among boys. They are more prone to cot death; are four times more likely to suffer from autism and attention deficit hyperactivity disorder and, according to analysis published in Proceedings of the National Academy of Sciences, are 24 per cent more likely to die in their first year than baby girls.

Still, their anxious mothers can console themselves that boys who avoid or overcome early hurdles, will generally go on to earn more, climb higher in their chosen profession and generally outstrip their sisters by the time they reach their late thirties.

Although, having said that, it won't make them any happier. In fact, studies show that these high-fliers will be significantly more miserable than their bright, ostensibly under-achieving female colleagues. But hey, there's a price to be paid for ruling the world.

So why are our gifted girls not fulfilling their career potential? Is it time to lob yet more brickbats at the glass ceiling?

Apparently not. According to an incendiary new book, there is no glass ceiling. Instead, women limit themselves - not because they can't handle the challenges at the top, but because they don't want to, thank you very much.

In The Sexual Paradox, clinical psychologist Susan Pinker tells us it's fatuous to pretend that girls and boys or men and women are the same, and it does neither gender any favour to do so. Contrary to our stubborn insistence that men and women are identical - and our belief that, given similar professional opportunities, will behave in the same way - the sexes are, in fact, driven by different motivations and respond very differently to competition.

"When you ask women what they want from work, they place great emphasis on the quality of their relationships at work and on working with people, not things," says Pinker. "An interest and an ability to contribute to a field are more powerful drivers for women, on average, than higher salaries, job security and benefits. Having a position of power is their lowest priority."

In her book, Pinker recounts fascinating Israeli research into competitiveness among eight-year-olds running races. When the children were timed running alone on a 40-metre track, there were no measurable differences between the sexes, and the girls ran just as fast as the boys. Then the children were matched to another child of comparable speed. Boys ran faster against an opponent, whereas the girls ran slower than against an opponent.

Moreover, when girls competed, the sex of their opponent mattered. Boys' performance improved whether they competed against boys or girls. Girls performed less well when running against other girls and faster when running against boys.

What conclusion we may draw says a lot about our own attitudes as a society; do we need to overcome this "problem" by boosting girls' competitiveness? Do we need to hold boys back so girls can be as "good" as them? Or do we simply accept that girls aren't the same as boys ?

Some girls, of course, exhibit just as much ambition as the boys, and it's not always edifying. Anyone who watched BBC's The Apprentice on Wednesday cannot have failed to notice the arrogance of the participants, male and female. They blithely announced they didn't care about other people's feelings, and one woman compared herself to an attack dog.

No wonder there's a general perception that those women who do ascend to the heights of power are tougher than men. Sir Alan Sugar, no slouch himself when it comes to unreconstructed views - he has openly said he is wary of employing women in case they become pregnant - claims that women employers are more ruthless than men.

This might account for the fact that this week we also learnt that men are "cowering in a world filled with bossy females", and feel undervalued and depressed. A survey by entertainment television channel DMAX revealed that men are calling for what American academics have dubbed a "menaissance" - a return to traditional manliness, when men derived status from being the main breadwinners.

This picture of injured male pride isn't borne out by the facts, however. There's no doubting women's capabilities: 60 per cent of students are female, as are almost two thirds of medical students. Yet in the uppermost echelons of virtually every profession, women are hugely under-represented.

According to the International Centre for Women Leaders at Cranfield School of Management, among FTSE 100 companies, just 11 per cent of directorships are held by women. Figures from the British Medical Association for 2006 show that in England, women represent 37 per cent of all hospital medical staff, but only 25 per cent of consultants and just seven per cent of consultant surgeons.

Last month a report in Economic Journal showed that women look lower down the career ladder in order to find jobs that allow them to spend time with their families, and as many as a third of female managers take lower-skilled jobs after having a child.

But Pinker believes that, far from being systematically discriminated against, women are exercising a conscious choice by opting for a healthy work-life balance. And by being prepared to make financial sacrifices, they end up far happier in their jobs than men.

"Around 20 per cent of women are single-mindedly focused on their careers and will happily devote themselves completely to their job the way a man would, and do just as well if not better than male colleagues," says Pinker. "But the majority of women have a broader view of happiness that's not usually compatible with reaching the extremes of their profession."

Economists in Britain, America, Canada, Japan and Sweden have found that women - despite taking home less pay - consistently rate themselves as happier in their jobs than men, something that has been dubbed "the gender paradox". But, interestingly, as women rise up the corporate ladder and the pressures increase, their satisfaction drops to male levels.

"There's an element of volition in women's choices that simply isn't being recognised," says Pinker. "The idea persists that women are victims who can't control their own destiny."

So just what will happen to the next generation of girls? Will they aim for the boardroom, or, more likely, will they continue to reject the testosterone-fuelled 24/7 culture that promotion invariably entails?

It will be fascinating also to see how we, their mothers, respond when our gifted daughters end up juggling children and careers in part-time jobs for which they are shockingly overqualified. We might wring our hands a little, but will any of us, hand on heart, wish we'd brought up an attack dog instead?

• The Sexual Paradox by Susan Pinker (Atlantic) is available from Telegraph Books for £11.99 + £1.25 p&p. To order call 0870 428 4112 or go to www.books.telegraph.co.uk